#338 Host OS list doesn't agree with the ZIP specification

[Takashi Toyama]

The following host OS list in CPP/7zip/Archive/Zip/ZipHandler.cpp doesn't agree with the ZIP specification.

namespace NArchive {
namespace NZip {

static const char * const kHostOS[] =
{
    "FAT"
  , "AMIGA"
  , "VMS"
  , "Unix"
  , "VM/CMS"
  , "Atari"
  , "HPFS"
  , "Macintosh"
  , "Z-System"
  , "CP/M"
  , "TOPS-20"
  , "NTFS"
  , "SMS/QDOS"
  , "Acorn"
  , "VFAT"
  , "MVS"
  , "BeOS"
  , "Tandem"
  , "OS/400"
  , "OS/X"
};

The list seems to be for GZip, not for ZIP.

https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT says

   4.4.2.2 The current mappings are:

    0 - MS-DOS and OS/2 (FAT / VFAT / FAT32 file systems)
    1 - Amiga                     2 - OpenVMS
    3 - UNIX                      4 - VM/CMS
    5 - Atari ST                  6 - OS/2 H.P.F.S.
    7 - Macintosh                 8 - Z-System
    9 - CP/M                     10 - Windows NTFS
   11 - MVS (OS/390 - Z/OS)      12 - VSE
   13 - Acorn Risc               14 - VFAT
   15 - alternate MVS            16 - BeOS
   17 - Tandem                   18 - OS/400
   19 - OS X (Darwin)            20 thru 255 - unused

In particular, Windows NTFS is displayed as TOPS-20.

[Takashi Toyama]

I'm sorry. I made a mistake about where to post.
I will make a patch immediately.

A minimal patch:

[Igor Pavlov]

read appnote from info-zip:

          0 - FAT file system (DOS, OS/2, NT)      + PKWARE 2.50+ VFAT, NTFS
          1 - Amiga
          2 - OpenVMS
          3 - Unix
          4 - VM/CMS
          5 - Atari ST
          6 - HPFS file system (OS/2, NT 3.x)
          7 - Macintosh
          8 - Z-System
          9 - CP/M
          ---------------------------------------------------------------------
               PKWARE assignment             | Info-ZIP assignment
          -----------------------------------|---------------------------------
          10 - Windows NTFS                  | TOPS-20
               (since PKZIPW 2.50, but       | (assigned Oct-1992,
                not used by any PKWARE prog) |  no longer used)
          11 - MVS                           | NTFS file system (WinNT)
                                             | (actively used by Info-ZIP's
                                             |  Zip for NT since Sep-1993)
          12 - VSE                           | SMS/QDOS
          ---------------------------------------------------------------------
          13 - Acorn RISC OS
          14 - VFAT file system (Win95, NT)     [Info-ZIP reservation, unused]
          15 - MVS [PKWARE describes this assignment as "alternate MVS"]
          16 - BeOS (BeBox or PowerMac)
          17 - Tandem
          18 - OS/400 (IBM)                  | THEOS
          19 - OS/X (Darwin)
          20 thru 29 - unused
          30 - AtheOS/Syllable
          31 thru 255 - unused

[Takashi Toyama]

I see what you mean. And I know that a number of programs use 11 for NTFS.
However, as Info-ZIP's appnote says, TOPS-20 is no longer used.
Is there a problem with assigning 10 (and 11) to NTFS except the unity or reversibility?

It's a matter of visualization only, not data logic.

[Igor Pavlov]

Why 10 for ntfs, if nobody uses it?

[Takashi Toyama]

As far as I know, a fork of the minizip and its derivatives use 10 on Windows systems.
Anyway, lets's close ticket.
Thank you for your feedback.

[Igor Pavlov]

If so, try to find some example of such archive.
if there are no real examples, we don't need to change it.